fix README.md formatting

README.md

@@ -1,17 +1,29 @@
-`krust` is a [k-mer](https://en.wikipedia.org/wiki/K-mer) counter--a bioinformatics 101 tool for counting the frequency of substrings of length `k` within strings of DNA data. It's written in Rust and run from the command line. It takes a fasta file of DNA sequences and will output all canonical k-mers (the double helix means each k-mer has a [reverse complement](https://en.wikipedia.org/wiki/Complementarity_(molecular_biology)#DNA_and_RNA_base_pair_complementarity)) and their frequency across all records in the given fasta file. 
+# `krust`
+
+`krust` is a [k-mer](https://en.wikipedia.org/wiki/K-mer) counter--a bioinformatics 101 tool for counting the frequency of substrings of length `k` within strings of DNA data. It's written in Rust and run from the command line. It takes a fasta file of DNA sequences and will output all canonical k-mers (the double helix means each k-mer has a [reverse complement](https://en.wikipedia.org/wiki/Complementarity_(molecular_biology)#DNA_and_RNA_base_pair_complementarity)) and their frequency across all records in the given fasta file.
+
+Run `krust` on the test data* in the [`krust` Github repo](https://github.com/suchapalaver/krust), searching for kmers of length 5, like this:
+
+```bash
+    cargo run --release 5 cerevisae.pan.fa > output.tsv
+```
 
-Run `krust` on the test data* in the [`krust` Github repo](https://github.com/suchapalaver/krust), searching for kmers of length 5, like this:  
-```$ cargo run --release 5 cerevisae.pan.fa > output.tsv```  
 or, searching for kmers of length 21:  
-```$ cargo run --release 21 cerevisae.pan.fa > output.tsv``` 
 
-`krust` prints to `stdout`, writing, on alternate lines:  
-```>{frequency}```  
-```{canonical k-mer}```   
-```>{frequency}```  
-```(canonical k-mer}```  
-...  
+```bash
+    cargo run --release 21 cerevisae.pan.fa > output.tsv
+```
+
+`krust` prints to `stdout`, writing, on alternate lines:
+
+```bash
+    >{frequency}  
+    {canonical k-mer}
+    >{frequency}  
+    {canonical k-mer}  
+    ...
+```  
 
 `krust` uses the [`rust-bio`](https://docs.rs/bio/0.38.0/bio/), [`rayon`](https://docs.rs/rayon/1.5.1/rayon/), and [`dashmap`](https://docs.rs/crate/dashmap/4.0.2) Rust libraries.  
-    
+
 *Unusual, yes, to provide this data in the repo, but it's helped me spread word about what I'm doing.